At many roadway railroad crossings, pedestrian paths and sidewalks also cross the railroad track. Crossing gates, which typically are raised by default and lowered when a train approaches and crosses an intersection of a road and railroad track (i.e., a crossing), may be provided for roadway and pedestrian safety. There may be a separate gate for the roadway and the pedestrian path. At some intersections, the roadway gate and the pedestrian gate are raised and lowered by the same gate mechanism. Typically, this means that the same internal gearing of the gate mechanism drives both gates. Therefore, if a pedestrian manually raises the pedestrian gate, the internal gearing of the gate mechanism raises the roadway gate as well. This can create an unsafe situation whereby the railroad crossing appears to be clear to motorists even though a train is approaching.
To avoid this problem, some crossings use separate gate mechanisms for the roadway and pedestrian gates. This option, however, is undesirable because it is more expensive than single mechanism installations. Furthermore, single mechanism installations are already in place at countless railroad crossings, and replacing them with two-mechanism systems could be cost prohibitive for many railroad operators.
Thus, there is a need and desire for a mechanism to prevent the improper raising of the crossing gates when a train is approaching the crossing.